Combined Heat and Power

Converting waste heat to power

Combined heat-and-power facilities (also called cogeneration, or
cogen, plants) are designed to produce both heat and electricity
from a single heat source.

All thermal power plants produce excess heat while generating
electricity. This heat is often released into the natural
environment through cooling towers, flue gas or other means. Cogen
plants capture this excess heat -- which would be wasted in
conventional power plants -- and use it for heating purposes. This
means less fuel must be consumed to produce the same amount of
useful energy, resulting in lower costs and CO2
emissions.

The U.S. Department of Energy (DOE) has set an aggressive goal
to have combined heat and power comprise 20 percent of U.S.
generation capacity by 2030. The DOE says that currently the vast
majority of U.S. electricity generation does not make use of waste
heat, resulting in an average utility-generation efficiency of 34
percent since the 1960s. The energy lost from wasted heat in the
U.S. is greater than the total energy use of Japan.

ACCORDING TO THE UNITED STATES CLEAN HEAT & POWER
ASSOCIATION, COMBINED-HEAT-AND-POWER SYSTEMS
CURRENTLY:

• Produce almost 8 percent of U.S. electric power
• Save building and industry owners more than $5 billion per year
in energy costs
• Decrease energy use by almost 1.3 trillion BTUs per year
• Reduce NOx emissions by 0.4 million tons per year
• Reduce CO2 emissions by over 0.9 million tons per
year
• Prevent the release of over 35 million metric tons of carbon
equivalent into the atmosphere